This invention relates to a cancer diagnosis and treatment device, and more particularly to a cancer diagnosis and treatment device for simultaneously performing cancer diagnosis and treatment with laser beams having different wavelengths suitable for cancer diagnosis and treatment.
There has been developed a cancer diagnosis and treatment system for simultaneously performing diagnosis and treatment of a malignant tumor such cancer using laser beams having different wavelengths. In this system, a photosensitive material such as hematoporphyrin derivative (HpD), dihematoporphyrin ether/ester (DHE) Or the like, which has affinity to cancer foci and fluorescent characteristic, is beforehand injected through a vein of a patient so that the photosensitive material is selectively absorbed in the cancer foci, and then two kinds of laser beams having different wavelengths are irradiated to the cancer foci to perform diagnosis and treatment of the cancer. The photosensitive material, for example, HpD emits characteristic red fluorescence with two peaks at 630 and 690 nm when exposed to light of an appropriate exciting wavelength (405 nm), and thus a diagnosis of cancer is performed by detecting the fluorescence of HpD. On the other hand, HpD is excited into its excited state when exposed to light of 630 nm, and then its exciting energy is transferred to an oxygen (O.sub.2) within the body of the patient to excite and activate the oxygen, and the activated oxygen acts on the cancer focus and destroys it. Accordingly, the cancer diagnosis and treatment can be performed using a photosensitive material and two laser beams having different wavelengths located in an absorption spectral range of the photosensitive material.
FIG. 1 shows a conventional cancer diagnosis and treatment device comprising an ordinary endoscopic diagnosis system 1 for observing a malignant tissue 21 having cancer focus 21a with an endoscope 5, and an optical diagnosis and treatment system 2 for performing cancer diagnosis and treatment of the tissue through fluorescence of the photosensitive material and through a sterilizing photochemical reaction between the injected photosensitive material and cancer foci. The endoscopic diagnosis system 1 includes a light source 4 for irradiating a white light to the surface of the tissue 21 containing the cancer focus 21a to observe the malignant tissue 21, a light guide 6 of the endscope 5 for guiding the white light to the tissue 21, an image guide 8 for guiding an image light of the surface of the tissue 21 to a color camera 7, and a TV monitor 9 for displaying the image obtained by the color camera 7. On the other hand, the optical diagnosis and treatment device 2 includes a laser beam generating device comprising a fundamental laser beam generator 10 for emitting a fundamental laser beam, a diagnostic laser beam generator 11 for generating a laser beam for diagnosis (for example, having a wavelength of 405 nm) using the fundamental laser beam and a treating laser beam generator 12 for generating a laser beam for treatment (for example, having a wavelength of 630 nm for HpD) using the fundamental laser beam, and a changeover unit 13 for selecting one of the laser beams of the diagnostic and treating laser beam generators 11 and 12. These laser beams for cancer diagnosis and treatment are guided through a light guide 14 to the tissue 21.
When the hematoporphyrin derivative (HpD) at pH 7.4, which is formed by dissolving hematoporphyrin hydrochloride in a mixture of sulfuric acid and acetic acid, is used for intravenous injection, upon incidence of a laser beam of 405 nm to the tissue 21 in a diagnostic procedure, fluorescence with two peaks at 630 and 690 nm is emitted from the hematoporphyrin derivative within the tissue. The fluorescence is transmitted through a light guide 15 of the endoscope 5 to a spectroscope 16 in which a spectrum pattern 17 of the fluorescence is produced. The spectrum pattern 17 thus obtained is picked up by a high-sensitive camera 18 comprising, for example, an image intensifier and a silicon intensified target (SIT) camera to obtain a video signal of the spectrum pattern 17. The video signal outputted from the high-sensitive camera 18 is processed by an analyzer 19 to obtain a graphical spectrum image of the fluorescence, which is finally displayed on a TV monitor 20. The spectrum pattern 17 of the fluorescence has a structure having two peaks at 630 and 690 nm, which is characteristic of the fluorescence of HpD, and thus a spectroscopic range of the spectroscope 16 is set to 600 to 700 nm in wavelength. The tissue 21 having the cancer focus 21a is discriminated in the above diagnosis procedure. Thereafter, the laser beam (405 nm) for cancer diagnosis is switched to the laser beam (630 nm) for cancer treatment by the change-over unit 13, and the laser beam for cancer treatment is irradiated to only the cancer focus 21a to destroy only the cancer focus 21a.
FIG. 2 shows a conventional laser beam generating device used in the cancer diagnosis and treatment device as shown in FIG. 1, and comprises an excimer laser generator 22 serving as the laser beam generator 10 for emitting a laser beam of 308 nm, and two kinds of dye laser cells 23 and 24, serving as the diagnostic and treating laser beam generators 11 and 12 as shown In FIG. 1, which are excited by the laser beam of 308 nm from the excimer laser generator 22 to output laser beams of 405 and 630 nm, respectively. The laser beam (308 nm) of the excimer laser generator 22 is split into two laser beams by a beam splitter 29aand one of the laser beams is transmitted through a change-over unit 29 to the first dye laser cell 23 while the other is reflected by a reflector 29b and transmitted through the change-over unit 29 to the second dye laser cell 24. A dye of the first dye laser cell 23 is circulated by a dye circulating unit 25 and is excited by one laser beam from the excimer laser generator 22 to output a laser beam of 405 nm using a pair of reflectors 27. On the other hand, another kind of dye of the second dye laser cell 24 is also circulated by another dye circulating unit 26 and is excited by the other laser beam from the excimer laser generator 22 to output a laser beam of 630 nm using a pair of reflectors 28. These laser beams emitted from the first and second dye laser cells 23 and 24 are guided through a light guide 14 to the cancer focus 21a.
A laser beam produced by the excimer laser generator 22 has a high pulse height and thus is effectively used for cancer diagnosis and treatment. However, since a laser gas used for the excimer laser generator 22 has a shorter life time, it is difficult to maintain a stable oscillating operation in the excimer laser generator 22 for a long time. In addition, it is required to circulate the laser gas within the excimer laser generator 22 and to exchange an used laser gas for a new one, for example, every week. As a result, the conventional laser beam generating device thus constructed has disadvantages that the construction thereof is complicated and the operation thereof is practically unstabilized.